Relationship Between Inflammatory Composite Indexes And Prognosis Of Brain Metastases From Lung Adenocarcinoma

Objective: Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death all over the world.Brain is one of a common distant metastases site in lung cancer and with a poor prognosis.Inflammation is the hallmark of cancer,which plays an important role in the development and progression of cancer.Many studies have reported the prognosis value of Systemic Immune-inflammation Index(SII),Neutrophil to Lymphocyte Ratio(NLR),Platelet to Lymphocyte Ratio(PLR)in cancers.The aim of this article is to evaluate the value of these inflammatory composite indexes on the brain metastases from lung adenocarcinoma,in order to identify the best index to guide clinical practice.Methods: The clinical data of 227 patients with brain metastases from lung adenocarcinoma in our hospital from January 1,2013 to December 31,2019 were retrospectively analyzed.Clinical data collected and analyzed included:gender,age,smoking history,EGFR mutation,Karnofsky functional status(KPS),extracranial metastases,number of brain metastases,treatments on brain metastases and hematological parameters.SII,NLR,PLR were calculated by neutrophil ×platelet/lymphocyte,neutrophil/lymphocyte,platelet/lymphocyte.The last follow-up time was December 31,2019.The optimal cut-off values for SII,NLR,PLR was identified from the Receiver operating characteristic(ROC).The Chi-square test was used to analyze the relationship between inflammatory composite indexes and clinicopathological parameters.Survival analysis was performed using the Kaplan–Meier method and Log-Rank test was used in univariate analysis.The variables in univariate analysis with statistical significance were entered into the multivariate analysis.The comparison of the SII,NLR,PLR in prognostic ability by area under curve(AUC).P<0.05 was considered statistically significant.Results: The optimal values for NLR,PLR,SII were 1094.77,4.18,192.35.Median Survival Time(MST)was 15.0 months.Univariate analysis showed that gender,smoking history,EGFR mutation,KPS,number of brain metastases,treatments for brain metastases,SII,NLR,PLR were predictors of Overall Survival(OS)(P<0.05).Multivariate analysis identified EGFR mutation(HR: 0.550,95%CI: 0.361-0.838,P=0.005),KPS(HR: 0.782,95%CI: 0.645-0.949,P=0.013),treatments for brain metastases(HR: 0.755,95%CI: 0.640-0.890,P<0.001),number of brain metastases(HR: 1.512,95%CI: 1.062-2.154,P=0.022),SII(HR: 1.999,95%CI: 1.151-3.470,P=0.014)as independent prognostic factors correlated with OS.AUCs of SII,NLR,PLR were 0.621,0.586,0.611.Comparison of the AUCs showed that the prognostic ability of the SII was superior to the NLR and PLR.Conclusions: SII is an independent prognostic factor of brain metastases from lung adenocarcinoma among inflammatory composite indexes,which is superior to the NLR and PLR.